Swimming pools and spas often have lights which are located below the water level to illuminate water within the pool or spa. This is typically accomplished by mounting a light bulb within a fixture that is located in a water-tight cavity known as a “niche” formed in the wall of the pool or spa. The watertight cavity or niche typically has an outer lens that prevents water from entering the fixture or niche.
In many existing swimming pools and spas, incandescent light bulbs are mounted within the niches. In recent years it has become known to replace those existing incandescent light bulbs with LED light sources in order to conserve power, provide varied colors of light and/or obtain greater light intensity.
For example, U.S. Pat. No. 6,184,628 (Ruthenberg) describes the use of predetermined arrays of a plurality of different colored LED bulbs to replace an incandescent pool light where the plurality of different colored LED bulbs are wired in such a manner that the predetermined arrays of plurality of different colored LED bulbs activate at predetermined sequences for predetermined time intervals wherein the bulbs are encased in a lens. Even though LED bulbs are used, providing LED lighting fixtures with brightness to rival incandescent bulbs is still an issue, especially when not all of the LED bulbs are illuminated, as suggested in the '628 patent.
United States Patent Application Publication Nos. 20030048632 (Archer) entitled “Light Emitting Diode Pool Assembly” and 2004/0223320 (Archer et al.) entitled “Nicheless Pool Light System” describe an LED light assembly that has a reflective plate with a plurality of perforations formed through the reflective plate. LED bulbs protrude through the perforations in the reflective plate. A control circuit is selectively operable to produce light in a plurality of colors through the LED bulbs. The control circuit comprises a switch that, when activated a defined number of times, produces a plurality of at least light colors and light patterns, wherein each of the plurality of at least light colors and light patterns are selected based on the defined number of times the switch is activated.
United States Patent Application Publication No. 20070159833 (Netzel et al.) entitled “LED Pool and Spa Light” describes a lighting fixture that includes a heat sink having a first mounting portion attached to a housing. A first circuit board containing LEDs is mounted to a first side of a second mounting portion of the heat sink. A second circuit board include an LED control circuit is mounted to a second side of the second mounting portion. A multi-layer circuit board includes a heat-dissipating core bonded to first and second dielectric substrates, which are bonded to first and second electrically conductive layers. An electrical conductor extends through a through-hole in the board to electrically connect the first and second conductive layers. An electrical insulator inside the through-hole electrically isolates the core from the conductor. A transparent cover is shaped to cause downwardly projecting light rays emitted from the LEDs to be refracted more than upwardly projecting light rays. The cover also includes vertically extending projections for horizontally refracting light.
United States Patent Application Publication No. 20060187652 (Doyle) entitled “LED Pool or Spa Light Having Unitary Lens Body” describes a light emitting diode pool or spa lamp bulb having at least one light emitting diode with at least one lens body that is optically clear. The light emitting diode(s) is/are embedded in the lens body and the lens body is in direct contact with the water within the pool or spa.
However, the use of LED light sources to replace incandescent lights in swimming pool and spa underwater fixtures and niches has been subject to certain limitations and difficulties. For example, because LED's produce substantial amounts of heat, the power of the LED's used in the replacement light source has, in at least some applications, been limited by the tendency for heat to collect within the water-tight fixture or niche. Also, in at least some applications, when a plurality of LED's cast light though an existing lens positioned over the water-tight fixture or niche, a plurality of light columns or spots are projected through the water instead of a desired diffuse distribution of light through the pool water. Thus, there remains a need in the art for the development of new LED lighting systems which may be used to replace existing incandescent or LED light sources in swimming pool and spa light fixtures and niches.